Presently, telecommunications services providers that offer inter-exchange toll call service, as well regional toll call service, typically charge the subscriber making such calls by billing the subscriber's residence or business from which the calls originated. In some instances, a subscriber may wish to originate calls from other locations yet not have the cost for such calls charged to the originating number. To accommodate that need, some telecommunications service providers, such as AT&T offer calling card service whereby a subscriber can charge the cost of a call to a calling card account. In practice, telecommunications service providers offering calling card service combine the calling card charges with the other call charges billed to the subscriber's residence or business. Alternatively, the telecommunication service provider may render a separate bill for such calling card charges. As a convenience, some telecommunications services providers now allow a subscriber to bill calling card charges to any of several commercial credit cards, such as Mastercard, Visa, Discover or American Express credit cards.
While traditional calling card service affords telephone subscribers the flexibility of making calls from locations other than their home or office, subscribers utilizing this service do not generally have the ability to budget for the call charges. Typical telecommunications service provider calling card accounts do not afford the subscriber the ability to set a limit on call charges. The credit limit, if any, on most calling card accounts usually is very high, representing the total credit worthiness of the subscriber. Most subscribers that subscribe to calling card service do not want their maximum credit limit on their card as the ordinary budget limit for telecommunication call charges.
As an alternative to traditional calling card service, telecommunication service providers such as AT&T now offer pre-paid telephone card service. A subscriber obtains pre-paid card service by purchasing a telephone card denominated in a currency amount representing a corresponding value (level) of service. The service provider issuing the card records the denominated amount in an account and typically prints the account number on the card, as well as a telephone number dialed to obtain the pre-paid service.
To obtain the pre-paid service, the subscriber dials the telephone number on the card whereupon, the telephone communications service provider prompts the subscriber to enter the pre-paid card account number. If the account number is valid, and the account has a sufficient balance, the telecommunications service provider then affords the subscriber the ability to place a telephone call to a called party. Upon establishing the call, the telecommunications service provider decrements the account balance in accordance with the running cost of the call. Should the account balance fall below a prescribed amount (representing a prescribed amount of call time, say one minute), the telecommunication service provider then warns the subscriber placing the call of the remaining call time. If the subscriber attempts to continue the call beyond the remaining call time, the telecommunications service provider terminates service. U.S. Pat. No. 4,706,275, issued Nov. 10, 1987, in the name of Zvi Kamil, purports to describe such a pre-paid card service.
Unlike traditional calling card service, pre-paid card service affords a subscriber the opportunity to budget for telecommunication call costs. A subscriber that wishes to spend only a certain sum for telecommunication costs can purchase one or more calling cards that collectively represent the budgeted amount for call costs. Unfortunately, traditional calling cards offer no flexibility in terms of exceeding the credit balance associated with the card. As discussed, telecommunications service providers offering traditional pre-paid calling card service invariably terminate a pre-paid card call once call cost exceeds the balance remaining on the pre-paid card. While the some pre-paid cards offer the subscriber an opportunity to replenish the card balance, the subscriber must do so during a separate call. Thus, with traditional pre-paid card service, subscribers run the risk of service termination once the pre-paid card account balance falls below the cumulative call cost.
Thus, there is need for a call billing mechanism that avoids the disadvantage associated with traditional calling call and pre-paid card service.